Sometimes you just want a leisurely float through the blue. Other times, you want to kick that experience up a gear for something truly memorable. These unique dive sites might make your pulse quicken from technical trickiness, breathtaking wildlife encounters and sheer beauty.

Fakarava’s Tumakohua Pass

Fakarava, French Polynesia

This UNESCO Biosphere Reserve plays host to hundreds of grey reef sharks, joined by tigers, lemons, hammerheads, and multiple reef sharks. This channel draws in the high concentration of toothy travelers due to nearly 20,000 camo groupers who arrive each June and July to spawn. The groupers themselves are no slouch to encounter, often paralleling the sharks in size — though come nightfall they are no match when the finned friends start hunting in packs.

Local Operator: Top Dive

Mahengetang Active Underwater Volcano

Sangihe Islands, Indonesia

This unholy trinity is a volcano triad. First, an active underwater volcano spews sulfur-scented, 96-degree water, bubbles bursting through a web of cracks. Then there’s the base of active above-ground volcano Karenetang, whose occasional rumblings vibrate bubbling visitors. Finally, pass by the extinct volcano with its system of tight, confined lava flow tubes. Massive soft corals of various shapes and hues await divers as they work their way through hazy thermoclines that stripe the water throughout the dive.

Local Operator: Two Fish Divers

Magic Pelagic Dive

Kailua-Kona, Hawaii

Night dives give the average diver a thrill. Blackwater diving brings that experience to the next level. Heading miles offshore into the deepest Pacific Ocean waters off the Big Island, you will hang suspended from a 60-foot tether over 4000 feet of sea to watch the open ocean, or pelagic, animals drift by on their diurnal vertical migration. Perfectly clear larval fish, invertebrates, siphonophores, cephalopods, ctenophores, salps, squid—even hunting dolphins or sharks glow under the lights as they rise to feed. If you think you’ve seen it all, this is the dive for you.

Local Operator: Jack’s Diving Locker

The Washing Machine

Exumas, Bahamas

Any drift dive with a stiff current can get the blood pumping, but “washing machine” sites take that next level as they whip divers into a spin cycle of head-over-fins fun. Experiences range from mild to wildly dangerous in destinations like Palau, Galapagos, and Tobago, with downdrafts sometimes extending past a safe dive profile. This Bahamian spot features an isolated circular tide that tumbles divers into a swirling ride dropping to 40 feet before sweeping you right back up to 15 feet to coast over a sea ledge. The section can be avoided by the faint of heart or those wanting to film friends rocking and rolling before joining them on the healthy coral-crusted sea ledge, home to sea turtles and lazy nurse sharks.

Local Operator: Dive Exuma

Princess Alice Seamount

Pico, Azores

Although the Big Island of Hawaii’s night dive might be the most well-known manta spotting locale, this big blue pinnacle dive is tops for descending on a line amongst a massive school of ever-circling daytime sicklefin devil rays or mobulas (accompanied by massive tuna, jacks and ’cudas) from June through October. Add to this cetaceous “spring break”— blue whales, fin whales, sei whales, humpback whales, and sperm whales pass by en route to their northern summer foraging grounds.

Local Operator: Season Challenge

Hole of Ha

Corfu, Greece

This picturesque site is one of the reasons Corfu is viewed globally as a top cavern diving locale. In this particular dive, the trip through the sea cave and glowing blue crevasse leads to the interior of a mountain. A collapsed, roof-free section allows divers a unique view of the tree-ringed opening while illuminating the underwater stalactites and fossilized conch shells with beautiful shimmering streaks.

Local Operator: Achilleon Diving Center

Lionfish Hunting Dive

Boca Beach Bay, Curacao/Southern Aruba

Get a spike to the pulse and do a local reef a solid by joining in a lionfish spearing expedition. Although safety is key, spotting the beautiful but reef-devastating invasive fish will perk up most divers, followed by the spearing itself to remove the threat to indigenous critters. But that’s where the excitement might just begin, as very friendly resident morays will be most interested in any trophies that take too long to be stashed into a zookeeper. For those with a need for speed, pair the hunt with a Solar-Powered Diver Propulsion Vehicle (DPV) to reach remote reefs in need of a hand.

Local Operators: Boca Beach Ocean Club; Aruba LionFish Initiative Foundation at Aruba Bob Snorkeling & Scuba

Blue Hole

Dahab, Egypt

Inherent adrenaline follows any place nicknamed “Diver’s Cemetery.” Most of these cases arise from those trying to push their limits without trimix training or safety protocols to deal with the inevitable narcosis that kicks in while trying to swim below the site’s famous arch. At 184 feet, the wall opens into an 80-foot-long archway out to the Red Sea. Divers need to listen to local dive professionals who are happy to properly train those determined to experience this glorious sight, and not be lulled into a sense of complacency by the fact that the Blue Hole appears to be a simple shore dive.

Local Operator: Fantasea Divers